On Sat, Aug 21, 2021 at 01:17:36PM +0300, Kalle Valo wrote:

Kees Cook [off-list ref] writes:

quoted

On Thu, Aug 19, 2021 at 04:19:37PM +0300, Kalle Valo wrote:

quoted

Kees Cook [off-list ref] writes:

quoted

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() so memset() doesn't get confused about writing
beyond the destination member that is intended to be the starting point
of zeroing through the end of the struct. Additionally split up a later
field-spanning memset() so that memset() can reason about the size.

Cc: Kalle Valo <redacted>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: ath11k@lists.infradead.org
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <redacted>

To avoid conflicts I prefer taking this via my ath tree.

The memset helpers are introduced as part of this series, so that makes
things more difficult. Do you want me to create a branch with the
helpers that you can merge?

Is this patch really worth the extra complexity? Why can't I apply this
ath11k patch after the helpers have landed Linus' tree? That would be
very simple.

Not singularly, no. But I have a bit of a catch-22 in that I can't turn
on greater FORTIFY strictness without first fixing the false positives,
and I can't fix the false positives in "other" trees without those trees
first having the helpers that get introduced by the FORTIFY series. :)

Anyway, since we're close to the merge window anyway, the FORTIFY series
won't land in 1 release at this point regardless, so I'll just get
the helpers landed and we can do the individual pieces once the merge
window closes.

Wheee :)

-- 
Kees Cook